1. wxThread changes (detached/joinable) for MSW and docs updates
2. wxUSE_GUI=0 compilation for MSW (use vc6dll.t with tmake) and many small
fixes related to this
3. an attempt to make wxLog more MT friendly
4. a small fix for wxRegConfig: it doesn't create empty unused keys any
more (SetPath() would always create a key, now it's deleted if it was
empty)